Early endothelial dysfunction in cholesterol-fed rabbits: a non-invasive in vivo ultrasound study.

BACKGROUND: Endothelial function in hypercholesterolemic rabbits is usually evaluated ex vivo on isolated aortic rings. In vivo evaluation requires invasive imaging procedures that cannot be repeated serially. AIM: We evaluated a non-invasive ultrasound technique to assess early endothelial function in rabbits and compare data with ex vivo measurements. METHODS: Twenty-four rabbits (fed with a cholesterol diet (0.5%) for 2 to 8 weeks) were given progressive infusions of acetylcholine (0.05–0.5 μg/kg/min) and their endothelial function was assessed in vivo by transcutaneous vascular ultrasound of the abdominal aorta. Ex vivo endothelial function was evaluated on isolated aortic rings and compared to in vivo data. RESULTS: Significant endothelial dysfunction was demonstrated in hypercholesterolemic animals as early as 2 weeks after beginning the cholesterol diet (aortic cross-sectional area variation: -2.9% vs. +4% for controls, p < 0.05). Unexpectedly, response to acetylcholine at 8 weeks was more variable. Endothelial function improved in 5 rabbits while 2 rabbits regained a normal endothelial function. These data corroborated well with ex vivo results. CONCLUSION: Endothelial function can be evaluated non-invasively in vivo by transcutaneous vascular ultrasound of the abdominal aorta in the rabbit and results correlate well with ex vivo data

Tadoussac : sentinelle ornithologique de la forêt boréale au parc national du Saguenay

Les suivis démographiques d'espèces animales réalisés dans des sites stratégiques permettent de détecter les cas problématiques en matière de gestion et de conservation de la faune. L'Observatoire d'oiseaux de Tadoussac, situé dans le parc national du Saguenay, est une organisation ornithologique qui recueille, depuis 1993, des données sur les oiseaux de proie et les passereaux de la forêt boréale, particulièrement sur des espèces en difficulté. On présente ici cinq séries de données, obtenues à l'Observatoire d'oiseaux de Tadoussac, qui illustrent les tendances démographiques de quelques représentants de l'avifaune québécoise et qui mettent en évidence certains cycles de population

Platelet-Activating Factor Induces Th17 Cell Differentiation

Th17 cells have been implicated in a number of inflammatory and autoimmune diseases. The phospholipid mediator platelet-activating factor (PAF) is found in increased concentrations in inflammatory lesions and has been shown to induce IL-6 production. We investigated whether PAF could affect the development of Th17 cells. Picomolar concentrations of PAF induced IL-23, IL-6, and IL-1β expression in monocyte-derived Langerhans cells (LCs) and in keratinocytes. Moreover, when LC were pretreated with PAF and then cocultured with anti-CD3- and anti-CD28-activated T cells, the latter developed a Th17 phenotype, with a significant increase in the expression of the transcriptional regulator RORγt and enhanced expression of IL-17, IL-21, and IL-22. PAF-induced Th17 development was prevented by the PAF receptor antagonist WEB2086 and by neutralizing antibodies to IL-23 and IL-6R. This may constitute a previously unknown stimulus for the development and persistence of inflammatory processes that could be amenable to pharmacologic intervention

Insights on post-breeding movements from a northeastern population of Canada Warblers (Cardellina canadensis)

ABSTRACT : The study of migratory songbird transition periods, such as the post-breeding period, is complex because birds undertake different types of movements that vary in space and time. Nonetheless, it is important to understand the extent and duration of the territory and specific sites use to identify human activities likely to affect the species’ survival. Individuals from different regional populations may exhibit specific movements during the various phases of their annual cycle, and therefore conservation actions must be adapted. We studied a population of Canada Warblers (Cardellina canadensis) from the Saguenay region of Quebec, Canada, in the northeastern part of the species’ breeding range. We used a coordinated radio-telemetry network (Motus) to determine the residence time within the breeding territory, dates and times of departure, and early fall migration routes of 18 adult birds. We expected individuals to leave by mid-August and to migrate through the eastern flyway, along the Atlantic Coast. Six tracked individuals remained on their breeding territory until early September, corresponding to a residence time of approximately 90 days. These individuals left just after sunset on their day of departure. Twelve individuals departed earlier, and in the daytime, before the end of August; their earlier departure was likely for a purpose other than migration. Nine individuals were detected outside their breeding territory along the Atlantic migratory flyway: four migrated through the Great Lakes region, one in the Great Appalachian Valley, three along the Atlantic Coast or coastal plain, and one with an undetermined route. Our results suggest that adult Canada Warblers remain in the Saguenay region longer than expected, and that, although some individuals remain close to their breeding territory during the post-breeding period, others may use surrounding territories prior to initiating their fall migration. Our results will allow regional conservation managers to recommend that regional industry postpone the timing of certain activities that could negatively affect the species’ survival. Our study highlights the importance of fine-scale studies focused on specific periods of migratory songbird annual cycles to fill important knowledge gaps for understanding of the ecology of their species. RÉSUMÉ : L'étude des périodes de transition de passereaux migrateurs, comme la période post-nuptiale, est complexe car les oiseaux entreprennent différents types de déplacements qui varient dans l'espace et le temps. Néanmoins, il est important de comprendre l'étendue et la durée de l'utilisation du territoire et de sites spécifiques pour qu'on puisse déterminer quelles activités humaines sont susceptibles d'affecter la survie de l'espèce. Les individus de différentes populations régionales peuvent présenter des déplacements spécifiques au cours des diverses étapes de leur cycle annuel, et les activités de conservation doivent donc être adaptées. Nous avons étudié une population de Parulines du Canada (Cardellina canadensis) de la région du Saguenay au Québec, Canada, située dans la partie nord-est de l'aire de nidification de l'espèce. Nous avons utilisé un réseau coordonné de radiotélémétrie (Motus) pour déterminer le temps de résidence dans le territoire de nidification, les dates et les heures de départ, et les routes de migration au début de l'automne de 18 oiseaux adultes. Nous nous attendions à ce que les individus quittent à la mi-août et migrent par la voie de migration de l'est, le long de la côte atlantique. Six individus sont restés sur leur territoire de nidification jusqu'à début septembre, soit un temps de résidence d'environ 90 jours. Ces individus ont quitté juste après le coucher du soleil le jour de leur départ. Douze individus sont partis plus tôt, et de jour, avant la fin du mois d'août; leur départ précoce avait sans doute un but autre que la migration. Neuf individus ont été détectés en dehors de leur territoire de nidification le long de la voie de migration de l'Atlantique : quatre ont migré par la région des Grands Lacs, un dans la vallée des Appalaches, trois le long de la côte atlantique ou de la plaine côtière, et un dont nous n'avons pu déterminer l'itinéraire. Nos résultats indiquent que les Parulines du Canada adultes restent dans la région du Saguenay plus longtemps que prévu et que, bien que certains individus restent à proximité de leur territoire de nidification pendant la période postnuptiale, d'autres peuvent utiliser des territoires environnants avant d'entreprendre leur migration automnale. Nos résultats vont permettre aux gestionnaires de la conservation de recommander à l'industrie régionale de reporter le moment d'activités qui pourraient nuire à la survie de l'espèce. Nous soulignons l'importance de mener des études à l'échelle fine visant des périodes spécifiques du cycle annuel des passereaux migrateurs afin de combler les lacunes importantes dans la compréhension de l'écologie de ceux-ci

Effect of Aquaculture-Related Diets on the Long-Term Performance and Condition of the Rock Crab, Cancer irroratus

Shellfish and salmonid aquaculture operations in Eastern Canada attract several mobile epibenthic species as a result of added structural complexity and increased food availability (bivalve fall-off and waste salmonid feed). It is not clear whether the aggregation of predators and scavengers below coastal farms contributes positively or negatively to their population dynamics, due to concerns about the quality of food items found under farms. We conducted an 18-month laboratory study to investigate the effect of diets composed of 1) mixed items, 2) mussels (Mytilus edulis), and 3) salmonid feed on the performance and condition of the rock crab, Cancer irroratus. Diet had no impact on crab survival but several negative consequences were observed in crabs fed the salmonid feed diet when compared to the mixed diet: reduced 1) moulting rates during the second growing season, 2) inter-molt growth, 3) gonad and hepatopancreas indices, 4) hemolymph dissolved compounds, 5) hepatopancreatic glycogen, and 6) shell hardness. Crabs fed the mussel diet had similar performance and condition when compared to the mixed diet. Fatty acid composition of muscle, gonad, and hepatopancreas tissues revealed that a salmonid feed diet decreased n3/n6 ratio when compared to a mixed or a mussel diet; those differences were mostly due to increases in the proportions of terrestrial (18:1n9 and 18:2n6) and decreases in proportions of marine essential (20:5n3 and 22:6n3) fatty acids. Together, these results point to a minimal impact of a mussel-only diet on crabs, whereas the salmonid feed diet resulted in negative impacts on condition. Our experimental results explored the consequences of a ‘worst-case scenario’ in which crabs were forced to feed on a single item for a long period of time; the realized impact in field settings will depend on other factors such as consumption of alternate food items underneath a farm, proportion of time spent in farms, and level of overlap between crab habitat and aquaculture facilities

Habitat loss on the breeding grounds is a major contributor to population declines in a long-distance migratory songbird

Many migratory species are declining and for most, the proximate causes of their declines remain unknown. For many long-distance Neotropical migratory songbirds, it is assumed that habitat loss on breeding or non-breeding grounds is a primary driver of population declines. We integrated data collected from tracking technology, community science and remote sensing data to quantify migratory connectivity (MC), population trends and habitat loss. We quantified the correlation between forest change throughout the annual cycle and population declines of a long-distance migratory songbird, the Connecticut warbler (Oporornis agilis, observed decline: −8.99% yr−1). MC, the geographic link between populations during two or more phases of the annual cycle, was stronger between breeding and autumn migration routes (MC = 0.24 ± 0.23) than between breeding and non-breeding locations (MC = −0.2 ± 0.14). Different Connecticut warbler populations tended to have population-specific fall migration routes but overlapped almost completely within the northern Gran Chaco ecoregion in South America. Cumulative forest loss within 50 km of breeding locations and the resulting decline in the largest forested patch index was correlated more strongly with population declines than forest loss on migratory stopover regions or on wintering locations in South America, suggesting that habitat loss during the breeding season is a driver of observed population declines for the Connecticut warbler. Land-use practices that retain large, forested patches within landscapes will likely benefit breeding populations of this declining songbird, but further research is needed to help inform land-use practices across the full annual cycle to minimize the impacts to migratory songbirds and abate ongoing population declines

Outcomes and care practices for preterm infants born at less than 33 weeks’ gestation: A quality-improvement study

BACKGROUND: Preterm birth is the leading cause of morbidity and mortality in children younger than 5 years. We report the changes in neonatal outcomes and care practices among very preterm infants in Canada over 14 years within a national, collaborative, continuous quality-improvement program. METHODS: We retrospectively studied infants born at 23–32 weeks’ gestation who were admitted to tertiary neonatal intensive care units that participated in the Evidence-based Practice for Improving Quality program in the Canadian Neonatal Network from 2004 to 2017. The primary outcome was survival without major morbidity during the initial hospital admission. We quantified changes using process-control charts in 6-month intervals to identify special-cause variations, adjusted regression models for yearly changes, and interrupted time series analyses. RESULTS: The final study population included 50 831 infants. As a result of practice changes, survival without major morbidity increased significantly (56.6% [669/1183] to 70.9% [1424/2009]; adjusted odds ratio [OR] 1.08, 95% confidence interval [CI] 1.06–1.10, per year) across all gestational ages. Survival of infants born at 23–25 weeks’ gestation increased (70.8% [97/137] to 74.5% [219/294]; adjusted OR 1.03, 95% CI 1.02–1.05, per year). Changes in care practices included increased use of antenatal steroids (83.6% [904/1081] to 88.1% [1747/1983]), increased rates of normothermia at admission (44.8% [520/1160] to 67.5% [1316/1951]) and reduced use of pulmonary surfactant (52.8% [625/1183] to 42.7% [857/2009]). INTERPRETATION: Network-wide quality-improvement activities that include better implementation of optimal care practices can yield sustained improvement in survival without morbidity in very preterm infants

Outcomes and resource usage of infants born at ≤ 25 weeks gestation in Canada

Objectives: To determine the outcomes and resource usage of infants born at ≤ 25 weeks gestational age (GA). Methods: Retrospective study of infants born between April 2009 and September 2011 at ≤ 25 weeks\u27 GA in all neonatal intensive care units in Canada with follow-up in the neonatal follow-up clinics. Short-term morbidities, neurodevelopmental impairment, significant neurodevelopmental impairment, and resource utilization of infants born at ≤ 24 weeks were compared with neonates born at 25 weeks. Results: Of 803 neonates discharged alive, 636 (80.4%) infants born at ≤ 25 weeks\u27 GA were assessed at 18 to 24 months. Caesarean delivery, lower birth weight, and less antenatal steroid exposure were more common in infants born ≤ 24 weeks as compared with 25 weeks. They had significantly higher incidences of ductus arteriosus ligation, severe intracranial hemorrhage, retinopathy of prematurity as well as longer length of stay, central line days, days on respiratory support, days on total parenteral nutrition, days on antibiotics, and need for postnatal steroids. Neurodevelopmental impairment rates were 68.9, 64.5, and 55.6% (P=0.01) and significant neurodevelopmental impairment rates were 39.3, 29.6, and 20.9% (P\u3c0.01) for infants ≤ 23, 24, and 25 weeks GA, respectively. Postdischarge service referrals were higher for those ≤ 23 weeks. Nonsurviving infants born at 25 weeks GA had higher resource utilization during admission than infants born less than 25 weeks. Conclusions: Adverse outcomes and resource usage were significantly higher among infants born ≤ 24 weeks GA as compared with 25 weeks GA

Association between admission temperature and mortality and major morbidity in preterm infants born at fewer than 33weeks\u27 gestation

Importance: Neonatal hypothermia has been associated with higher mortality and morbidity; therefore, thermal control following delivery is an essential part of neonatal care. Identifying the ideal body temperature in preterm neonates in the first few hours of lifemay be helpful to reduce the risk for adverse outcomes. Objectives: To examine the association between admission temperature and neonatal outcomes and estimate the admission temperature associated with lowest rates of adverse outcomes in preterm infants born at fewer than 33 weeks\u27 gestation.. Design, Setting, And Participants: Retrospective observational study at 29 neonatal intensive care units in the Canadian Neonatal Network. Participants included 9833 inborn infants born at fewer than 33 weeks\u27 gestation who were admitted between January 1, 2010, and December 31, 2012.. Exposure: Axillary or rectal body temperature recorded at admission.. Main Outcomes And Measures: The primary outcomewas a composite adverse outcome defined as mortality or any of the following: severe neurological injury, severe retinopathy of prematurity, necrotizing enterocolitis, bronchopulmonary dysplasia, or nosocomial infection. The relationships between admission temperature and the composite outcome as well as between admission temperature and the components of the composite outcome were evaluated using multivariable analyses.. Results: Admission temperatures of the 9833 neonates were distributed as follows: lower than 34.5°C (1%); 34.5°C to 34.9°C (1%); 35.0°C to 35.4°C (3%); 35.5°C to 35.9°C (7%); 36.0°C to 36.4°C (24%); 36.5°C to 36.9°C (38%); 37.0°C to 37.4°C (19%); 37.5°C to 37.9°C (5%); and 38.0°C or higher (2%). After adjustment for maternal and infant characteristics, the rates of the composite outcome, severe neurological injury, severe retinopathy of prematurity, necrotizing enterocolitis, bronchopulmonary dysplasia, and nosocomial infection had a U-shaped relationship with admission temperature (a \u3e 0 [P \u3c .05]). The admission temperature at which the rate of the composite outcome was lowest was 36.8°C (95%CI, 36.7°C-37.0°C). Rates of severe neurological injury, severe retinopathy of prematurity, necrotizing enterocolitis (95%CI, 36.3°C-36.7°C), bronchopulmonary dysplasia, and nosocomial infection (95%CI, 36.9°C-37.3°C) were lowest at admission temperatures ranging from 36.5°C to 37.2°C.. Conclusions And Relevance: The relationship between admission temperature and adverse neonatal outcomes was U-shaped. The lowest rates of adverse outcomes were associated with admission temperatures between 36.5°C and 37.2°C.